This invent ion relates to drag reducing slurries which are mixtures of drag reducing polymers and other materials which maintain the polymers in a suspension ready for immediate use without the need for mixing or other steps of preparation. Such a slurry is stored in use aboard a vessel or on land for use in other facilities and can be pumped immediately into the laminar region of a flow stream to reduce turbulence and drag.
Prior art slurries have proven to be unstable when stored for long periods and these polymers have been shown to be poorly disolved upon introduction into the flowstream. Since the drag reducing polymers such as polyethylene oxide and polyacrylamide resins and other well known drag reducing polymers identified in such publications as Transactions of the ASME of June 1972 pages 258-285 and several patents such as U.S. Pat. Nos. 3,350,338; 3,843,589; 3,727,570; 3,736,288; 3,734,873 absorb solvent, in this case water, immediately upon contact they tend to form cohesive viscous layers upon the particle surface and cause aggregation of particles and the formation of a solution resistive mass. In the slurry art this phenomenon is referred to as the formation of strings, globs and fish eyes. This phenomenon occurs due to the partial, delayed and uneven wetting that occurs when the slurry is pumped into the flowstream.
One possible solution would be to mechanically mix the slurry and water at least partially prior to injection into the flowstream. This is unfeasible since it would require a large scale investment in equipment and increases in weight and space requirements that would make the use of slurries altogether undesirable.